Improving dielectric strength of polyvinylidene fluoride by blending chains with different molecular weights

POLYMER

卷:190

Article

Fan, Benhui¹  Xing, Zhaoliang²  Bedoui, Fahmi³  Yuan, Jinkai⁴  Lu, Xiaoxin⁵  He, Delong¹  Zhou, Mingyu⁶  Zhang, Chong²  Dang, Zhimin⁷  Weigand, Steven^8,9  Bai, Jinbo¹ 

[1] Univ Paris Saclay, Cent Supelec, CNRS UMR 8579, Lab Mecan Sols Struct & Mat MSSMat, 8-10 Rue Joliot Curie, F-91190 Gif Sur Yvette, France

[2] Global Energy Interconnect Res Inst, State Key Lab Adv Transmiss Technol, Beijing 102211, Peoples R China

[3] Sorbonne Univ, Univ Technol Compiegne, Roberval UMR CNRS, F-7337 Compiegne, France

[4] Univ Bordeaux, Ctr Rech Paul Pascal, CNRS, UMR5031, F-33600 Pessac, France

[5] Univ Paris Saclay, Grp Elect Engn, Paris GeePs, CNRS UMR 8507,Cent Supelec, Paris, France

[6] Global Energy Interconnect Res Inst Europe GmbH, Kantstr 162, D-10623 Berlin, Germany

[7] Tsinghua Univ, Dept Elect Engn, State Key Lab Elect Syst, Beijing 100084, Peoples R China

[8] Northwestern Univ, Anl Argonne, IL USA

[9] DND CAT Synchrotron Res Ctr, Anl Argonne, IL USA

关键词: Dielectric strength;    Crystalline structure;    Molecular weights;   

DOI  :  10.1016/j.polymer.2020.122235

来源: Elsevier

【 摘 要 】

Polyvinylidene fluoride (PVDF), as an electroactive polymer, has been attracting increasingly attention for its broad potential applications ranging from film capacitors, actuators, to energy harvesters. The capability of a PVDF film to sustain a high working voltage is highly demanded to achieve these applications. Herein, we find that blending two PVDF polymers with low and high molecular weights can achieve higher dielectric strength (E-b = 479 MV/m) than either of the two original ones (PVDF-1 with Mw of similar to 180,000, E-b = 412 MV/m and PVDF-2 with Mw of similar to 441,000, E-b = 391 MV/m). The underlying synergetic effect is deduced from the analysis of the crystallization of PVDF by wide-angle X-ray diffraction and small-angle X-ray scattering from a synchrotron source. It involves crystallite polymorphism, the transition of crystalline phases, the variation of crystalline lattice spacing at different strain spaces, and the long periods and the distribution of crystallite sizes. Understanding these underlying influences is beneficial to process PVDF films with desirable and reliable dielectric properties.

【 授权许可】

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